In the breast milk pumps of the above kind known so far, the periodical opening and closing of the valve interrupting the suction flow is controlled by an electronic pulse generator. Herein electromagnetic valves are controlled by the control laid out respectively so that they open and close periodically to generate a pulsating suction effect.
In mechanical milkers for cattle so-called vacuum pulsators are used (See for example DE-AS 22 41 233, DE-OS 32 19 628, DE-PS 28 12 830), but their operational principle cannot be applied to a breast milk pump of the same kind as in these mechanical milkers the so-called milking cup (teat rubber) has two vacuum lines for each milking cup which have to be controlled by means of separate, but interacting valves. A known breast milk pump (EP 01 23 269 A2) is too awkward and too expensive for private use with its pneumatically actuated pump piston which is controlled by two valves.